Work

Gravitational entropy

Year: 2026

Type: article

Abstract: We formulate the classical gravitational entropy of a horizon as a Noether charge that does not require the notion of a temperature, and which is applicable to horizons that are not necessarily associated with black holes. This introduces a correction to the covariant phase space formalism that accounts for the configuration-dependence of the generating vector field conjugate to the charge. The vector field is related to the proposal of Bousso that the gravitational entropy of a region is determined by the lightsheet at its boundary. We test the formula on various black hole and cosmological horizons.

Source: Classical and Quantum Gravity

DOI: 10.1088/1361-6382/ae60de

Authors: Sangmin Choi, Malcolm J Perry

Institutions: Institute for Theoretical Physics Amsterdam, University of Amsterdam, University of Cambridge

Language: English

Topic: Black Holes and Theoretical Physics

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,325

Funders: European Commission, Science and Technology Facilities Council